Mechanical ventilation by placement of endotracheal and other ventilation tubes can be a necessity for patients for a variety of reasons. For example, patients receiving anesthetics may require ventilation to temporarily take over their natural breathing mechanism. Here mechanical ventilation is used only for a relatively short period of time. Patients suffering from respiratory failure, in contrast, may be intubated and ventilated for days, weeks, or even longer while in intensive care. Ventilation tubes which enter the trachea through a patient's mouth or nose are generally referred to as endotracheal tubes. Ventilation tubes which are inserted through an incision in the neck are usually referred to as tracheostomy tubes. In both cases, the devices will include a ventilation tube having a central lumen to provide for ventilation of the patient.
Ventilator-associated pneumonia (VAP) is an infection which occurs especially in patients who are on mechanical ventilation through an endotracheal or tracheostomy tube for a considerable amount of time. VAP is a medical condition that results from infection which floods the alveoli, the small, air-filled sacs in the lung responsible for absorbing oxygen from the atmosphere. It is known to be caused by the leakage of proximal fluids during intubation into the distal airways. VAP is distinguished from other kinds of infectious pneumonia by the different types of microorganisms responsible, the antibiotics used in treatment, the methods of diagnosis and the effective preventive measures. While community-acquired pneumonia is most often caused by S. pneumoniae, H. influenzae, or S. aureus, the organisms associated with VAP are most often Gram-negative bacteria, such as Pseudomonas aeruginosa. 
The occurrence of VAP leads to increased duration of ventilation and ICU stay and is associated with a high attributable mortality. VAP also leads to more and specific antibiotic use, increasing the risk of development of multidrug resistant bacteria.
A wide array of VAP prevention measures has already been undertaken. Generally, these measures consist of positional, physical and pharmacological interventions. In general these measures involve limiting exposure of the patient to resistant bacteria, discontinuing mechanical ventilation as soon as possible, and a variety of strategies to limit infection while the patient is intubated. Resistant bacteria are spread in much the same ways as any communicable disease. Proper hand washing, sterile technique for invasive procedures, and isolation of individuals with known resistant organisms are all mandatory for effective infection control.
Other recommendations for preventing VAP include raising the head of the bed to at least 30 degrees and placement of feeding tubes beyond the pylorus of the stomach. Antiseptic mouth washes such as chlorhexidine may also reduce the incidence of VAP.
The endotracheal or tracheostomy tube is a critical device in mechanical ventilation, as it is the tube connecting the patient to the ventilator, through which air is driven into the lungs. Following insertion of the tube into the trachea, a balloon (or cuff) around the tube is inflated, typically up to a maximum pressure of 30 cm H2O, which allows fixation of the tube. The cuff also prevents inflow of proximal secretions to the distal airways. As these secretions can be bacteriologically contaminated, the leakage of these secretions is considered to be one of the most important causes of VAP. Due to the presence of the cuff, these secretions will accumulate above the cuff. Adaptations to endotracheal or tracheostomy tubes to prevent leakage of secretions in the lungs and/or to “disinfect” the tube internally have been proposed, such as supraglottic secretion drainage (SSG), double-cuffed tubes, continuous or intermittent subglottic drainage, tubes with a polyurethane cuff (e.g. Kimberly-Clark Microcuff® endotracheal tubes) and silver-coated endotracheal or tracheostomy tubes (e.g. Agento® I.C. silver-coated endotracheal tube).
In spite of the use of these new types of endotracheal or tracheostomy tubes, the leakage of the proximal secretions to the distal airways still occurs. Consequently VAP is still diagnosed on a frequent basis.
Accordingly, there is a need for improved endotracheal or tracheostomy tubes or patient ventilation tubes which prevent the leakage of proximal secretions to the distal airways.